After having the Westone um3x for quite some time, i was wondering what the next logical upgrade would be? I've tried 535's, and w4's - while both were good, i didn't necessarily like them enough over the um3x to justify buying them (borrowed each of those off friends).

As far as universal iem's go - what is a good choice for an upgrade that i will get a noticeable improvement? I've read lots of great things about the 1+2 and se846...but before i jump into an investment that big, i was just wondering if there was anything in between what i have in the um3x and the ultra high end?